In the planning phase of a building, the building owner and the architect need to decide whether or not an elevator installation is to be installed in the building. During that process, building owners and architects increasingly consider parameters such as energy consumption, eco-friendliness and overall operational costs of elevator installations. In certain countries, the reliability of the public power grid is an additional parameter since power outages may shut down an elevator installation leaving it unavailable during a power outage.
Several approaches that address some of these considerations are known. For example, JP 4-272073 discloses a “clean” elevator system having solar cells that charge a battery. The battery provides energy for driving a motor of the elevator system. In addition, the battery absorbs regenerated energy provided by the motor when is acts as a power generator.
Also, CN101544332 describes an elevator system powered by a switchable power supply. The elevator system has a commercial power supply, a power supply input identification interface, an intelligent power supply controller, a power supply output identification interface, an elevator driving controller, a solar energy generating device and an energy storage. The solar energy generating device is connected with the power supply input identification interface and the energy storage; and the energy storage is connected with the power supply input identification interface and the elevator driving controller. The elevator is powered by a stand-by power supply supplied by the solar energy generating device, wherein the energy storage stores the electrical energy to ensure that the elevator runs normally in case that the commercial power supply is cut off.
Even though these approaches address some of the parameters building owners and architects increasingly consider, they are individual approaches and provide as such limited flexibility and adaptability to various circumstances. There is, therefore, a need for an alternative approach with improved flexibility and adaptability. Accordingly, the various embodiments of such an alternative approach disclosed herein relate to an energy management system, in which various operational modes regarding optimization of energy usage are integrated and which selectively executes these modes depending on at least one predetermined parameter of a variety of parameters.